Title: Ancient Pagan and Modern Christian Symbolism
Last Updated: November 17, 2012

http://www.gutenberg.org/files/38485/38485-h/38485-h.htm

With two exceptions, Figs. 4 and 9,—exhibits Christian emblems of the trinity or linga, and the unity or yoni, alone or combined; the whole being copied from Pugin's Glossary of Ecclesiastical Ornament (London, 1869). 

Fig. 1 is copied from Pugin, plate xvii., and indicates a doable anion of the trinity with the unity, here represented as a ring, Vanneau.

     * There is an able essay on this subject in No. 267 of the
     Edinburgh Review—which almost exhausts the subject—but is
     too long for quotation here.

...

It has been said by some critics that the figures above referred to are mere architectural fancies, which never had pretensions to embody a mystery; and that any designer would pitch upon such a style of ornamentation although profoundly ignorant of the doctrine of the trinity and unity. But this assumption is not borne out by fact; the ornaments on Buddhist topes have nothing in common with those of Christian churches; whilst in the ruined temple of the sun at Marttand, India, the trefoil emblem of the trinity is common. Grecian temples were profusely ornamented therewith, and so are innumerable Etruscan sculptures, but they do not represent the trinity and unity. It has been reserved for Christian art to crowd our churches with the emblems of Bel and Astarte, Baalim and Ashtoreth, linga and yoni, and to elevate the phallus to the position of the supreme deity, and assign to him a virgin as a companion, who can cajole him by her blandishment, weary him by wailing, or induce him to change his mind by her intercessions. Christianity certainly requires to be purged of its heathenisms.